It is known, for example in the context of cellular radio telephone systems, for the subscriber number of the telephone from which a call is originated to be transmitted in binary code to the telephone receiving the call. This is known in the art as Calling Line Identification (CLI).
Prior art telephones have been adapted to respond to CLI signals and have been provided with a facility for displaying the telephone numbers of incoming calls. Hence the user can see the telephone number before answering the call. Prior art telephones responsive to CLI have been provided with a specific number of designated memory locations, e.g. four, for storing the CLI number of an incoming call. This has the drawback that if more calls are received than the number of locations which have been reserved for CLI information then some information will necessarily be lost or not retained. For example if there are four CLI memory locations and five calls are received, the telephone number of one of the calls cannot be stored. It may be that one of the numbers already stored in the CLI memory is lost in order to keep a record of the four most recent calls, or simply that no further numbers are recorded once the CLI memory is full. Moreover, if a call is received from the same telephone number more than once, the whole number will be recorded on each occasion. This is a disadvantage because it does not efficiently use the CLI memory space and also because it is not easy for the user to assimilate that he has received a call from the same telephone number several times. Usually it is arranged that the CLI numbers are shown on the telephone display one at a time and in this case the user would have to remember the telephone number from one appearance to the next in order to realize that two (or more) calls were from the same number.
GB-A-2014825 discloses a telephone apparatus in which the telephone number of a caller is stored in a memory and can be recalled at a later stage if the call is not answered initially. A counter stores the total number of stored telephone numbers and this total can be displayed. However, this total is the total number of telephone numbers stored and gives no indication of how many times a particular telephone number has called.